(1) Field of the Invention
This invention relates to a refrigerating cycle, and more particularly to a refrigerating cycle which can be used in an automotive air conditioner in a manner selectively performing an operation in which the maximum cooling power is desired to be unleashed and an operation in which the most excellent coefficient of performance is attained.
(2) Description of the Related Art
An automotive air conditioner is operated under adverse service conditions. For instance, it has a compressor thereof driven by an engine whose rotational speed is largely changed. Therefore, a refrigerating cycle for the automotive air conditioner is configured to be properly serviceable even under such conditions. A generally known type of the refrigerating cycle for the automotive air conditioner uses a receiver and a thermal expansion valve.
This type of refrigerating cycle is so configured as to adiabatically compress a gaseous refrigerant with a compressor driven by the engine, condense the gaseous refrigerant compressed to a high temperature and a high pressure with a condenser, separate the condensed refrigerant into a gaseous refrigerant and a liquid refrigerant with a receiver, adiabatically expand the separated liquid refrigerant with a thermal expansion valve to thereby produce a low-temperature and low-pressure refrigerant and allow this refrigerant to be evaporated with an evaporator and then return to the compressor.
The conventional refrigerating cycle is somewhat configured to allow the maximum cooling power thereof to be unleashed when the compressor is driven by a constant rotational speed. Although the operation of the cycle providing the maximum cooling power is necessary under limited conditions, e.g. when the automotive air conditioner is started, it is preferable from the view point of energy saving that the cycle operates to provide a required refrigerating capability by a minimum power, i.e. with an excellent coefficient of performance, e.g. when it is in a steady operating condition.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a refrigerating cycle which is capable of performing both an operation in which the maximum cooling power thereof is desired to be unleashed and an operation in which the most excellent coefficient of performance is attained.
In order to accomplish the object, the present invention provides a refrigerating cycle including a compressor, a condenser, a receiver, an expansion device, and an evaporator, which are connected by a conduit line in the mentioned order, characterized in that a pressure-reducing device is arranged between said condenser and said receiver.
The above and other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the present invention by way of example.